Images

Kate Scharer examining striations along fault scarp while completing GPS survey of fault rupture.  Here the fault has about 2.6 m of horizontal displacement and 0.5 m of vertical.  The rake of the striations is 47 degrees.  Photo credit: Jamie Delano, USGS

USGS Pasadena Earthquake Response Coordinator surveys displaced rocks near the southern end of the surface rupture of the 5 July 2019 M7.1 Ridgecrest earthquake.  USGS photograph. Photo credit: Sue Hough, USGS

USGS Pasadena Earthquake Response Coordinator Sue Hough, surveys displaced rocks near the southern end of the surface rupture of the 5 July 2019 M7.1 Ridgecrest earthquake.  Photo credit: Sue Hough, USGS

Geologists with USGS, the California Geological Survey (CGS) and Naval Air Weapons Station China Lake (NAWS) worked together in response to the Ridgecrest earthquake sequence in California that occurred July 4-6, 2019. The earthquakes were large enough that the fault rupture reached the earth’s surface.

3,557 earthquakes recorded since July 4, 2019 above Magnitude 2

M6.4 12km W of Searles Valley, CA
2019-07-04 17:33:49 (UTC)
51,000+ responses via Did You Feel It?

M7.1 18km W of Searles Valley, CA
2019-07-06 03:19:53 (UTC)
42,000+ responses via Did You Feel It?

Kate Scharer (USGS) provides CO CAPT Paul Dale (Navy) with the field mapping team’s initial product, showing the surface fault rupture at NAWSCL as well as the temporarily deployed seismic and GPS sensors that were rapidly deployed. Contributions of field data from within the base were from CGS & USGS, and from outside the base were from Univ.

Kate Scharer (USGS) provides CO CAPT Paul Dale (Navy) with the field mapping team’s initial product, showing the surface fault rupture at NAWSCL as well as the temporarily deployed seismic and GPS sensors that were rapidly deployed. Contributions of field data from within the base were from CGS & USGS, and from outside the base were from Univ.

Two portable sensors: a strong motion sensor (to record strong shaking that can be felt) and a broadband sensor (to record weak motion for detecting small earthquakes) buried into the ground to detect earthquakes. These stations can be quickly deployed and send real-time data back to the USGS via cellular telemetry immediately after they are installed. 

USGS Earthquake Science Center Mobile Laser Scanning truck operated by Ben Brooks and Todd Ericksen scanning the surface rupture near the zone of maximum surface displacement of the M7.1 Searles Valley earthquake.

Fault rupture crosses dirt road, with California Geologial Survey vehicles for scale. Displacement at this location is primarily normal (vertical). Photograph taken near the northern end of the rupture resulting from the M7.1 Searles Valley earthquake.

USGS Research Geologists Christopher DuRoss and Jessica Thompson Jobe examine rupture resulting from the M7.1 Searles Valley earthquake.

Oblique photograph showing surface faulting from the M7.1 Searles Valley earthquake. The dirt track (center) is right-laterally offset approximately 2.5 m (~8 ft).

USGS Research Geologists Christopher DuRoss measures surface displacement resulting from the M7.1 Searles Valley earthquake.

California Geological Survey and USGS geologists and geophysicists with National Guard and Navy personnel view road damage from 3 to 5 feet of right-lateral motion near the expected maximum slip locality along the primary tectonic rupture associated with the M 7.1 event.

Scientists from USGS & California Geological Survey viewing vertical fault offset of ~12 +/- 3 foot high fault scarp near the expected maximum slip locality along the primary tectonic rupture associated with the M 7.1 event.

USGS Geologists Beth Haddon and Josie Nevitt measure fault displacement along the principal rupture.

USGS geologists Josie Nevitt and Beth Haddon make measurements of fault rupture.

USGS Geophysicists Elizabeth Cochran and Nick VanDerElst install a seismometer on the base.

USGS geodesist Todd Ericksen sets up GPS surveying equipment on July 5th.

USGS geophysicist Ken Hudnut demonstrating Drop Cover and Hold Technique during the foreshock sequence to the M7.1 Searles Valley earthquake.

Aerial view shot from Blackhawk helicopter overflight on July 6 of the zone of high surface displacement.